Roaster for coffee, peanuts, etc.



July 28, 1925.:

Y R. T. JOHNSTON noAs'rER Fon COFFEE, rmmu'rs, E'rc :s s'hets-sheet 1Filed Aug, 15. 1922 MJ. VE T ge l TTORNEYS.

July 2s, 192s. 1,547,655

R. T."J OHNSTON RoAsTER FOR COFFEE, PEANU'rs., ETC.

, Filed Aug, 15. 1922 s sheets-sheet 2 ATTORNEYS.

July 2s, 1925. A

R. T. JOHNSTON ROASTER FOR COFFEE, PEANUTS., ETC

Filed Aug. 15. 1922 3 Sheets-Sheet 3 INVENTOR:

- meme July ze, 1925.

UNITED STATES y nomi: a', :omis-rol, or m nimmer, nw snaar, melon ro'moins PATENT OFFICE.

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To all whom it may comm.'

it known that I, Boum T. Joint- `roN, a'citizen of the United States,residing at New Brunswichcounty ofMiddlesex, State of New Jersc haveinvented a new and useful Roaster or Coffee, Peanuts, Etc., of which thefollowing is a specification. In the present methods, commonly vogue inroasting a material such as coffee the coffee beans are roasted by theapplication thereto of direct heat in which the fumes and gases ofcombustion envelop the coee to a greater or les extent during the entireperiod of dehydration and w. Also in the present commercial met commonlyin vogue, gas is largely med and the llame is blown the coffee as with ablow torch,'the colfee being flowed past the flame by the action of therotary conveyor of the machine and receiving an a plication o llame toeach revolution of die linder.

By the action of the ame and the constant envelopment of the coee inthefum or gases of combustion, there is a tenden to urn out and-destroythe valuable of the coee, which are depended upon to give it the desiredaroma and preserve it from rapid deterioration after In the aforesaidcommercial methods in vogue, the deleterious action of the fumes andgases of combustion have in some instances proved so destructive that ithas necessitated the abandonment of the direct flame method, since theenvelo ment of the coffee in these fumes and p ucts of combustion duringthe entire roastmoperation has caused chemical changes in e delicateoils, which are depended upon to furnish the aroma of the coffee.

By my novel invention, which I have devised forv the purpose ofovercoming the aforesaid oijctpable features, I prplvig: meansfor eytinganroastng t coffee through the medium of ure heated air heatedindirectly and entire free from the burnt products of combustion, thispure heated air beingnerated in a separateY furnace and fo into thecoffee roasting chamber through a manifold at high velocity, which 1s soarranged and proporas to circulate the heated air systematlcally and raidly the roastmgchamberino erthatthe airwillabscrl the greatest possiblequantity of molsture 1n the roces of dehydration and surround the co eeuniformly in the iinal P B ot i h y my mventiro e rotary conve or of themacne keeps the co ee in constant motion, lifting and flowing it backthro the circulating heating medium, and c constantly uni orm action ofthe heated air on the coffee dries and roasts it uniformly and rapidldylwith a minimum heatgandinthiswa ecofeeisprocessed wlth the least possile loss of values.

I have further found that the uniformity of the roasting by my novelprocs is 4very noticeable, and this results from the systematicdistribution of heated air through the batch of coee which is constantlsurrounded by the pure circulating heate heating medium, the results ofmy novel process resulting in a decreased a superior aroma of the coffeeand in enhancing the preservation and keeping qualities o the cofeeafter roasting.

I have found from the practical use of my invention that the shrinkageloss is reducedfromtwotothreeper cent, sincethe dehydration is complete,and this decreased percentage of therefore represents the actual savingof the oils of the coffee, and coffee roasted by my novel process, byreason of the retention of the oils operation cannot take place untillout noticeable deterioration.

To the above ends my invention consists of a novel process and apparatusfor roasting coee, the novel features of which will beY hereinafterfully set forth and pointed out in the claims.

It further consists of other novel' features. of construction, all aswill be hereinafter fully set forth.

For the purpose of illustrating my invention, I have shown in theaccompanying dra forms thereof which are at presentpreerredbymgsincethewillgivein practice. satisfactory and able results,

. therein, will keep for several months with- Y although it is to beunderstood that the various instrumentalities of which my inventionconsists can be variously arranged and organized and that my inventionis, not limit to the precise arrangement and oranization of theseinstrumentalities as lgierein shown and described.

Fi re 1 represents a'front elevation of a co ee roaster, embodying myinvention. Figure 2 represents a plan view of Fig urel.

Figure 3 represents a diagrammatic sectional view of the inlet pipingand its adjuncts, whereby the heating medium is conveyed from its sourceto the roasting appliances, the secticm being taken on line 3--3 Fi re2. Y

Fil ure 4 represents a diagrammatic view of tlgie exhaust piping and itsadjuncts, whereby the heating medium is withdrawn or exhausted from theroasting appliances to the desired points.v

Figure 5 represents a section of the roasters on line 5-5 Figure 2.

Figure 6 represents on an enlarged scale a section on line 6-6 Figure 1.f Similar numerals kof reference indicate corresponding parts.

. In carrying out my invention, I employ a suitable furnace 1,1which canbe placed in any convenient point and piped to agroup one of of anynumber of roasters. The furnace is preferably built on the unit systemso that sections can be added as -additional roasters are installed, andany suitable form of furnace and any suitable heating medium or fuel, asoil, gas, coal, coke or the like can be employed and ,any automatic orsuitable yforni of heat regulation can be employed, which is maintainedat a fixed temperature, regardless of the number of roasters inoperation at one time.

As it will be apparent that any suitable form of furnace for heating theair used in the roasting operation may be employed, I have notundertaken to show or describe the same'in detail, but have merely shownsuch a furnace diagrammatically at the right hand portion of Figure 1.

The pure highly heated air having been created in the furnace iswithdrawn there-v from through the pipe 2, which leads to the main 3from which lead vertical branches 4, 5 and 6, see Fig. 3, which lead tothe horizontal branches 7, 8 and 9,`the latter leading to the manifolds26 in the coffee roasters 10, 11 and 12 respectively (see Fig. 2).Within the vertical branches 4, 5 and 6 are located the valves ordampers serving as hot air regulators as indicated at 13, 14 and 15.While I have shown' 'but three of the roasters, it will be evident thattheir number may be increased or diminished. according to requirement.

The horizontal branch 7 is provided with nozzles 19,20 and 21respectively. The construction of the coffee roasters 1,0, 11 and 12 andtheir agitators may be of any suitable or conventional type such as seenin Patents 1,128,101 and 1,313,020, and in Figure 5 I have shown oneconventional form of such roaster, which may be employed, wherein thecoee agitator or drum'22 is perforated and provided with the spiralblades 23, said barrel beingrotated by any suitable .means as the'drivenpinion 24 meshing with the gear' 25.*Y The manifold 26 which enters thebarrel 22 is constructed in cross section as seen dotted in Figure 1andy is provided with perforations 27, so that the pure heated airentering sad manifolds 26 from a branch (see Fig. 5) as 9 is caused toimpinge directly upon the batch of coee being processed.

Fromy the top of each roaster as 12 extends the connection 28, whichleads to the box 29 provided with the screens 30 serving as a chaff anddust separator from which leads the branch- 31 to the main exhaust pipe32. In like manner, froml the roaster 11 leads the branch 33 to the box34, which Ais provided with screens similar to those seen in Figure 5and already described, from which leads the branch 35 to the mainexhaust pipe 32. v In like manner, from the roaster 10 leads the branch36 to the box 37, which is also provided with the screens similar tothose seen in Figure 5, from whichv leads the pipe or branch 38 to themain exhaust pipe 32. The pipe 32 leads to the chamber 39, which has agate 40 therein, which controls the outlet pipes 41 and 42, said gate 40being operated from the exterior by the handle 43. The chamber 39 withits gate 40 forms a regulator for reconditioning the air and is providedwith a fresh air intake 44 commu nicating with the atmosphere.

The branch 41 leads directly to the blower 45, which is connected to thefurnace 1 by the pipe 46. The branch 42 leads to the stack 47, which isprovided with the damper 48, the products of combustion from the furnacebeing discharged through said stack.

When the gate 40 is in the position seendotted in Fig. 6, the air fromthe ovens is directed, through the pipe 42 into the stack, and fresh aironly is passed through the heater. When the, gate is in the positionseen in full lines in Figure 6 the greater portion of the air from theovens is reconditioned,

and only a; small portion of fresh air is used, as is evldent.

The operation is as follows -The pure highly heated air having beengenerated in the proper compartment of the urnace, passes therefromthrough the pipe 2, main 3, and vertical branches 4, 5 and 6, best seenVin Fig. 3, into the horizontal branches 7, 8 and 9, into thecommunicating manifolds as' 26, and passing through the ports 27 (see'Fi5) at a h igh velocity impmges onfthe co ee as it isagitated in the drum22, it being apparent that only pure heated 'air entirely free from theburnt products of combustion is utilized in my novel process. Each ofthe manifolds 26 is arranged and proportioned so as circulateA the pureheated air systematically and rapidly throughout the drum or roastingchamber 22, so that said air will ra idly absorb the greatest possiblequantity 0 moisture in the process of dehydration and surround thecoffee uniformly in the final process of roasting, the rotary conveyoror drum 22 keeping the coffee in constant motion and lifting and blowingit back through the pure, heated circulating air, whereby the coee isdried vand roasted uniformly and rapidly, with a minimum heat and isconsequently processed with the least possible loss of values.

The col'ee being constantly surrounded by the circulating heated air,which is systematically distributed through the batch results in a verynoticeable uniformity of the roast, a decreased shrinkage, a superioraroma, and the preservation or keeping qualities of the coffee afterroasting.

By my process the shrinkage loss is reduced from two to three per cent,and as it is evident that the roasting operation cannot take vplaceuntil dehydration is complete, this decreased percentage of shrinkagetherefore represents the, actual saving .of the oils of -the coffee Thedampers 13,

14 and 15 best seen in Fig. 3, serve as hot air regulators for thevertical pipes and the dampers 16, 17 and 18, best seen in Figpl, serveas cold air regulators for checking the roasts, and can also` be used tocompletely cool the roasts when desired.v

Accurate heat control is an essential requirement of a commercial coffeeroasting apparatus and in my device the regulation of the heat is underthe instant control `of the operator and ranges fromthe highesttemperature required for roasting to cool atmospheric air, drawn in pastthe dampers. 16, 17 and 18 to each roaster to check the roast as may bedesired. j

The practice of applying suicient water to a freshly roasted ateh tobalance atmosphere conditions is followed in many roasting plants, andwater can be applied in my process in atomized form by drawing 1t intothe roasting chamber through the f' spraying nozzles or atomizers, 19,20, or 21, slmultaneously with the ingress of the cool atmospheric aircontrolled by the dampers 16, 17 and 18.

The nozzles or atomizers, 19, 20 and 21 construction, which it isunnecessary -to describe in detail and may be rovided with valves as 49as will be -un erstood from dust from the air exhausted or withdrawnfrom the roasters through the pipes 31, 35, 38 and 32l (see Fig. 4)since when the chalt` and dust was returned to the heating elements inthe heater 1, the high temperature therein, burned the chaff and theheated air with which the coffee was roasted was fouled with the smokeof combustion.

I accordingly devised the separators 29, 34 and 37, whose internalconstruction will be apparentfrom lFigure 5, and whose function\ is toremove the dust and chaff from the air before it is returned to theblower through the exhaust main 32. By the manipulation of the gate 40,which has already been explained, the exhaust or used heated air can bewithdrawn from the roasters and conducted either in whole or in part tothe stack 47 or 'to the blower 45, as is evident, the reconditioned airbeing conducted from the pipe 46 to the pipe 2 by any suitable means,which it is unnecessary to describe in detail.

It will be -apparent that in my invention the pure heated air isgenerated in a separate furnace and piped to the roasting machines sothat one furnace can be placed at any convenient point andjpiped to agroup of any number of roasters, and the furnace being built on the unitsystem, ad-

ditional sections can be added as additional roasters are installed,which is a great advantage over the present method of direct fires,where each roaster must necessarily embodyrits own furnace, with all theinconvenience and wastefulness of individual fires. It will further beapparent that my novel process is adaptable to all constructions ofroasting' machine of any of the standard or conventional types now inuse, as it utilizes only about one half the blower and motor equipmentused with standard machines, and requires only a sepvmay be of anyconventional or standard I claim as new and desire to secure byLettersPatent, is

1. The herein described method of roasting material, which consists vinheatmg pure air, next directing the pure heated air unmixed with anyproducts of combustion upon the batch of material to be roasted, and

lastly checking the roast by an admixture of atmospheric air with saidpure heated air.

2. The herein described method of roasting a material, which consists 1nheating pure air, next directing the pure heated air unmixed with anyproductsof combustion upon the batch of material to be roasted,`

and, lastly, introducing into said heated air, an admixture of vapor andatmospheric air.

3. The herein described method of roasting a material, which consists inheating pure air, conducting the pure heated air to the batch ofmaterial to be roastedtmain'- taining said material in a state ofagitation during the roasting operation, separating the chaff and dustfrom the heated air subsequent to its utilization in the roastingoperation, and lastly, exhausting the heated air after purification to astack or furnace.

4. The herein described method of roasting a material, which consists inheating pure air, conducting the pure heated air to the batch ofmaterial to be roasted, maintaining said material in a state ofagitation during the roasting operation, commingling vapor andatmospheric air with said heated air, separating the impurities fromsaid heated air subsequent to its utilization in the roasting operation,and lastly, exhausting the heated air after purification to theatmosphere or to a furnace for reheating it.

5. The herein described method of roasting a material, which consists inheating pure air, conducting the pure heated airto the batch of coffeeto be roasted, maintaining said material in a state of agitation duringthe roasting loperation, commingling vapor and atmospheric air with saidheated air, separating the impurities from said heated air subsequent toits utilization in l the roasting operation, exhausting the purifiedheated air partly .into a stack and reheating device, and, lastly,commingling fresh air with said purified air prior to its introductioninto said stack and reheating device.

6. In a roasting device of the character stated, means for heating pureair, means for agitating the material to be roasted, a

roximity .niospheric air with said heated air prior to the impingementof the latter upon the inaterial.

8. In a device of the character stated, means for heating pure air,means for agitatingl the material to be roasted, a manifold aving portsthe-rein in proximity to which the material is maintained in a state ofagitation, and means for conducting the pure heated air into saidmanifold from which it is discharged upon said material, in combinationwith means for commingling atmospheric air and vapor with said heatedair prior to the impingement of the latter upon the coffee.

9. The combination of a material roaster having therein means foragitating material, air heating means, an apertured manifold fordischarging the superheated air unmixed with products of combustion intosaid material, an exhaust pipe leading from said roaster, a separator insaid exhaust pipe, and an exhaust fan connected with said exhaust pipe.

10. The combination of a material roaster having therein means foragitating material, air heating means, an apertured manifold fordischarging the heated air unmixed with products of combustion into andaround said material While in a state of agitation, an exhaust pipeleading from said roaster, a separator in said exhaust pipe, an exhaustfan, a furnace having al stack, a chamber in said exhaust pipe having agate therein, and connections controlled by said gate from said chamberto said fan and stack.

11. The combination of a material roaster having therein means foragitating coffee, air heating means, an apertured manifold fordischarging the heated air unmixed with products of combustion into andaround said material While in a state of agitation, an exhaust pipeleading from said roaster, a separator in said exhaust pipe, an exhaustfan, a furnace having a stack, a chamber in said exhaust pipe having agate therein, and connections controlled by said gate from said chamberto said fan and stack, in combination with a fresh air intake openingleading into said chamber.

12. The combination of a vmaterial roaster in a state ,l

having therein means for agitating the material, air heating means, anapertured manifold for discharging the heated air unmixed with productsof combustion into and around said coee'while in a state of itation, 'anexhaust pipe leading from sai? roaster, a separator in said exhaustpipe, an exhaust fan, a furnace having a stack, a chamber in saidexhaust pipe having a gate therein, and

connections controlled by said gate from said 1 chamber to said fan andstack, in combination with a fresh air intake opening leading into saidchamber, and a pipe leading from said fan to said furnace.

' ROBERT T. JOHNSTON. Witnesses:

ELIZABETH H. HARDING, M. T. HARDING.

